Continuously variable transmissions are known. Continuously variable transmissions include a driven clutch operatively coupled to a drive clutch through a belt. The drive clutch is coupled to an input shaft of the continuously variable transmission and the drive clutch is coupled to an output shaft of the continuously variable transmission. As is known in the art, as the rotation speed of the input shaft varies, the drive clutch, the driven clutch, and the belt cooperate to vary the rotation speed of the output shaft. Typically, the drive clutch, the driven clutch, and the belt are positioned within a housing and ambient air is pulled into the housing to assist in cooling the drive clutch, the driven clutch, and the belt.
The present disclosure relates to continuously variable transmissions. By way of example, the present disclosure relates to systems and methods to cool one or more components of a continuously variable transmission, systems and methods to monitor a temperature of one or more components of a continuously variable transmission vehicles, and an outer cover for a housing of a continuously variable transmission.
In exemplary embodiment of the present disclosure, a continuously variable transmission for coupling a drive shaft and a driven shaft is provided. The continuously variable transmission comprising a housing including a base having a first opening adapted to receive the drive shaft and a second opening adapted to receive the driven shaft and a cover being coupled to the base. The cover and the base cooperating to define an interior of the housing. The continuously variable transmission further comprising a drive clutch positioned within the interior of the housing and adapted to be operatively coupled to the drive shaft and a driven clutch positioned within the interior of the housing and adapted to be operatively coupled to the driven shaft. The drive clutch including a first drive clutch sheave and a second drive clutch sheave moveable relative to the first drive clutch sheave. The driven clutch being operatively coupled to the drive clutch and including a first driven clutch sheave and a second driven clutch sheave moveable relative to the first driven clutch sheave. The continuously variable transmission further comprising a first number of air supply conduits coupled to the housing, each providing non-recycled air from an exterior of the housing to the interior of the housing through at least one air supply openings in the housing; and at least one air outlet conduit coupled to the housing. A second number of the first drive clutch sheave, the second drive clutch sheave, the first driven clutch sheave, and the second driven clutch sheave are directly contacted by the non-recycled air provided by the first number of air supply conduits. The second number being greater than the first number and the second number is at least equal to three.
In one example, the first number is one. In a variation thereof, the second number is four. In another example, the second number is four. In still another example, the first number is two. In a variation thereof, the second number is three. In a further example, the second number is three.
In still a further example, an first air supply opening in the housing is positioned within an envelope of a first side of the driven clutch perpendicular to a rotational axis of the driven clutch and a first air supply conduit of the first number of air supply conduits is positioned to provide non-recycled air through the first air supply opening in the housing to contact the first side of the driven clutch. In a variation thereof, the first air supply opening is positioned laterally outboard of the driven clutch. In another variation thereof, the rotational axis of the driven clutch extends through the first air supply opening. In yet another variation thereof, the first supply opening is centered around the rotational axis of the driven clutch. In still another variation thereof, the housing includes a flat surface which overlaps an outer portion of the first side of the driven clutch and cooperates with the driven clutch to define a gap between the driven clutch and the housing which causes air to be accelerated towards the drive clutch when the driven clutch is rotating about the rotational axis of the driven clutch. In a refinement of the variation, the gap has a generally constant thickness between the driven clutch and the housing. In another refinement of the variation, the gap has a thickness between the driven clutch and the housing of about 9 millimeters. In still another refinement of the variation, the gap generates a low pressure region which draws air from the first supply opening and accelerates the air to about 60 meters per second. In yet another refinement of the variation, the housing has a smooth profile from proximate the first air supply opening to the flat surface. In yet still another refinement of the variation, the housing has a smooth profile from proximate the first air supply opening to the flat surface, a portion of the smooth profile having a plunger shape.
In still a further example, an air diverter is supported by the housing and is positioned between the drive clutch and the driven clutch. The air diverter having an upper portion, a lower portion, and a waist portion between the upper portion and the lower portion. The air diverter channels air to travel from proximate the driven clutch to proximate the drive clutch in a first region in the interior of the housing above the upper portion of the air diverter and channels air to travel from proximate the drive clutch to proximate the driven clutch in a second region in the interior of the housing below the lower portion of the air diverter. In a variation thereof, the lower portion of the air diverter has an air peeler. The air peeler dividing the air into a first portion which is channeled to travel from proximate the drive clutch to proximate the driven clutch in the second region in the interior of the housing below the lower portion of the air diverter and a second portion which is directed back towards the drive clutch. In a refinement of the variation, the air diverter extends from the flat surface of the housing in a first direction and a pocket to receive the drive clutch extends from the flat surface of the housing in a second direction, opposite the first direction. The housing further including a channel extending from the pocket to the flat surface of the housing, the channel being positioned below the air diverter.
In another exemplary embodiment of the present disclosure, a continuously variable transmission for coupling a drive shaft and a driven shaft is provided. The continuously variable transmission comprising a housing including a base having a first opening adapted to receive the drive shaft and a second opening adapted to receive the driven shaft and a cover being coupled to the base. The cover and the base cooperating to define an interior of the housing. The cover having a unitary body. The continuously variable transmission further comprising a drive clutch positioned within the interior of the housing and adapted to be operatively coupled to the drive shaft. The drive clutch including a first drive clutch sheave and a second drive clutch sheave moveable relative to the first drive clutch sheave. The continuously variable transmission further comprising a driven clutch positioned within the interior of the housing and adapted to be operatively coupled to the driven shaft. The driven clutch being operatively coupled to the drive clutch and including a first driven clutch sheave and a second driven clutch sheave moveable relative to the first driven clutch sheave. The unitary body of the cover including a flat surface which overlaps an outer portion of a first side of the driven clutch which is perpendicular to a rotational axis of the driven clutch and the flat surfaces cooperates with the driven clutch to define a gap between the driven clutch and the housing which causes air to be accelerated towards the drive clutch when the driven clutch is rotating about the rotational axis of the driven clutch.
In one example, the gap has a generally constant thickness between the driven clutch and the housing. In another example, the gap has a thickness between the driven clutch and the housing of about 9 millimeters. In a further example, the unitary body of the cover has a smooth profile from proximate a first air supply opening to the flat surface. In a variation thereof, the first air supply opening is positioned within an envelope of the first side of the driven clutch perpendicular to a rotational axis of the driven clutch. A first air supply conduit is coupled to the housing and positioned to provide non-recycled air through the first air supply opening in the unitary body of the cover to contact the first side of the driven clutch. In another variation thereof, a portion of the smooth profile having a plunger shape.
In a further example, the unitary body of the cover includes an air diverter positioned between the drive clutch and the driven clutch. The air diverter having an upper portion, a lower portion, and a waist portion between the upper portion and the lower portion. The air diverter channels air to travel from proximate the driven clutch to proximate the drive clutch in a first region in the interior of the housing above the upper portion of the air diverter and channels air to travel from proximate the drive clutch to proximate the driven clutch in a second region in the interior of the housing below the lower portion of the air diverter. In a variation thereof, the lower portion of the air diverter has an air peeler. The air peeler dividing the air into a first portion which is channeled to travel from proximate the drive clutch to proximate the driven clutch in the second region in the interior of the housing below the lower portion of the air diverter and a second portion which is directed back towards the drive clutch. In a refinement thereof, the air diverter extends from the flat surface of the unitary body of the cover in a first direction and a pocket to receive the drive clutch extends from the flat surface of the unitary body of the cover in a second direction, opposite the first direction. The unitary body of the cover further including a channel extending from the pocket to the flat surface of the unitary body of the cover. The channel being positioned below the air diverter.
In a further exemplary embodiment of the present disclosure, a method of cooling a continuously variable transmission which includes a housing, a drive clutch positioned within an interior of the housing and including a first drive clutch sheave and a second drive clutch sheave moveable relative to the first drive clutch sheave, and a driven clutch positioned within the interior of the housing and including a first driven clutch sheave and a second driven clutch sheave moveable relative to the first driven clutch sheave is provided. The method comprising the steps of coupling a first number of air supply conduits to the housing, each providing non-recycled air from an exterior of the housing to the interior of the housing through at least one air supply opening in the housing; and directing the non-recycled air to directly contact a second number of the first drive clutch sheave, the second drive clutch sheave, the first driven clutch sheave, and the second driven clutch sheave. The second number being greater than the first number and the second number is at least equal to three.
In still a further exemplary embodiment of the present disclosure, a method of cooling a continuously variable transmission which includes a housing, a drive clutch positioned within an interior of the housing and including a first drive clutch sheave and a second drive clutch sheave moveable relative to the first drive clutch sheave, and a driven clutch positioned within the interior of the housing and including a first driven clutch sheave and a second driven clutch sheave moveable relative to the first driven clutch sheave is provided. The method comprising the steps of coupling a first air supply conduit to a first air supply opening in the housing, the first air supply opening being positioned within an envelope of a first side of the driven clutch, the first side being perpendicular to a rotational axis of the driven clutch; providing a flat surface which overlaps an outer portion of the first side of the driven clutch and cooperates with the driven clutch to define a gap between the driven clutch and the housing; and providing an airflow path extending from proximate the first air supply opening to the flat surface, the airflow path having a smooth profile.
The above mentioned and other features of the invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings. These above mentioned and other features of the invention may be used in any combination or permutation.
Corresponding reference characters indicate corresponding parts throughout the several views. Unless stated otherwise the drawings are proportional.